Pub Date : 1984-01-01DOI: 10.1179/030716984803274800
M. Mclean, A. Strang
AbstractA review is given of the range of properties of superalloys that can be affected by trace elements and their dependence on various solutes showing the different response of a given alloy to different solutes, the different sensitivities of different alloys to the same solute, and the importance of both microstructural form and mechanical-test conditions. The main emphasis is on understanding and modelling the mechanisms by which trace elements can influence mechanical properties significantly. Trace elements at ppm concentrations are only likely to be effective with respect to mechanical behaviour if there is a mechanism leading to local enrichment. The various means of achieving this are considered including different types of segregation and the formation of precipitate particles. The factors leading to segregation of solute to, and the embrittlement of, grain boundaries are considered. Guidelines evolved to identify embrittling species in ferrous alloys are modified to predict those most likely...
{"title":"Effects of trace elements on mechanical properties of superalloys","authors":"M. Mclean, A. Strang","doi":"10.1179/030716984803274800","DOIUrl":"https://doi.org/10.1179/030716984803274800","url":null,"abstract":"AbstractA review is given of the range of properties of superalloys that can be affected by trace elements and their dependence on various solutes showing the different response of a given alloy to different solutes, the different sensitivities of different alloys to the same solute, and the importance of both microstructural form and mechanical-test conditions. The main emphasis is on understanding and modelling the mechanisms by which trace elements can influence mechanical properties significantly. Trace elements at ppm concentrations are only likely to be effective with respect to mechanical behaviour if there is a mechanism leading to local enrichment. The various means of achieving this are considered including different types of segregation and the formation of precipitate particles. The factors leading to segregation of solute to, and the embrittlement of, grain boundaries are considered. Guidelines evolved to identify embrittling species in ferrous alloys are modified to predict those most likely...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"47 1","pages":"454-464"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78201181","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274747
R. Whittle, V. Scott
AbstractThe reaction zone produced on a series of austenitic alloys by boronizing at 950°C consists of two distinct layers, an outer layer of M B phase and an inner, M2B compound. Beneath the boride layers, appreciable quantities of chromiumrich boride form at grain boundaries, giving an irregular, or ‘toothed’ interface. The dry lvear behaviour of boronized samples exhibits a transition from mild to severe wear, once the load applied to the specimen exceeds a critical value. The transition marks the point where stresses developed by the applied load are sufficient to deform the substrate and thence to promote mechanical instability of the boride coating. Little difference between the wear characteristics of M B and M2B was observed, but a toothed structure appears beneficial, because it increases substrate rigidity and enhances adhesion between boride and metal. Comparison with wear data for untreated austenitic alloys shows that boronizing substantially improves tribological properties, provided that th...
{"title":"Sliding-wear evaluation of boronized austenitic alloys","authors":"R. Whittle, V. Scott","doi":"10.1179/030716984803274747","DOIUrl":"https://doi.org/10.1179/030716984803274747","url":null,"abstract":"AbstractThe reaction zone produced on a series of austenitic alloys by boronizing at 950°C consists of two distinct layers, an outer layer of M B phase and an inner, M2B compound. Beneath the boride layers, appreciable quantities of chromiumrich boride form at grain boundaries, giving an irregular, or ‘toothed’ interface. The dry lvear behaviour of boronized samples exhibits a transition from mild to severe wear, once the load applied to the specimen exceeds a critical value. The transition marks the point where stresses developed by the applied load are sufficient to deform the substrate and thence to promote mechanical instability of the boride coating. Little difference between the wear characteristics of M B and M2B was observed, but a toothed structure appears beneficial, because it increases substrate rigidity and enhances adhesion between boride and metal. Comparison with wear data for untreated austenitic alloys shows that boronizing substantially improves tribological properties, provided that th...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"7 1","pages":"522-529"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90160450","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1984-01-01DOI: 10.1179/030716984803274549
A. Thuvander, A. Melander, W. Hutchinson
AbstractLow-carbon steel containing 0·07 wt-% phosphorus has been heat treated in the laboratory in a manner designed to simulate an industrial continuous-annealing process. The resulting structures have been examined by optical metallography and X-ray diffraction, while mechanical properties were determined from tensile tests. Process variables investigated were: (i) hot-band ‘coiling’ temperature, (ii) cold-rolling reduction, (iii) time and temperature of annealing, and (iv) the quenching temperature of the sheet after annealing. A standard overaging treatment was given in all cases. Strength levels of the steel sheets were rather insensitive to processing treatments, but increased somewhat with lower coiling and annealing temperatures as a result of grain refinement. Both ductility and plastic anisotropy were favoured by a higher coiling temperature, and an optimum combination of properties was foundfor the 67% cold-rolled sheet annealed for 80 s at 750°C. With heavier cold reductions, the optimum anne...
{"title":"Processing of phosphorus-alloyed lovv-carbon steel sheet by continuous annealing","authors":"A. Thuvander, A. Melander, W. Hutchinson","doi":"10.1179/030716984803274549","DOIUrl":"https://doi.org/10.1179/030716984803274549","url":null,"abstract":"AbstractLow-carbon steel containing 0·07 wt-% phosphorus has been heat treated in the laboratory in a manner designed to simulate an industrial continuous-annealing process. The resulting structures have been examined by optical metallography and X-ray diffraction, while mechanical properties were determined from tensile tests. Process variables investigated were: (i) hot-band ‘coiling’ temperature, (ii) cold-rolling reduction, (iii) time and temperature of annealing, and (iv) the quenching temperature of the sheet after annealing. A standard overaging treatment was given in all cases. Strength levels of the steel sheets were rather insensitive to processing treatments, but increased somewhat with lower coiling and annealing temperatures as a result of grain refinement. Both ductility and plastic anisotropy were favoured by a higher coiling temperature, and an optimum combination of properties was foundfor the 67% cold-rolled sheet annealed for 80 s at 750°C. With heavier cold reductions, the optimum anne...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"43 1","pages":"105-114"},"PeriodicalIF":0.0,"publicationDate":"1984-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79928453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-03-01DOI: 10.1179/030716983803291929
V. Voller, J. Moore, N. Shah
AbstractThe aim in this paper is to develop further and extend the application of the mathematical descriptions based on the previously developed local solute redistribution equation’ for the alloy-solidification process. To this end, a modified local solute redistribution equation for unidirectional solidification is presented and, using channel perturbation analysis based on this equation, a condition is developed for unstable flow and possible channel segregation which relates the interdendritic fluid velocity to the isotherm velocity. On assuming this condition to hold, a physical description related to the modified local solute redistribution equation is proposed, and a possible mechanism is presented for local remelting and the formation of channel segregation.
{"title":"Modification of mathematical analyses and related physical descriptions used to describe channel segregation","authors":"V. Voller, J. Moore, N. Shah","doi":"10.1179/030716983803291929","DOIUrl":"https://doi.org/10.1179/030716983803291929","url":null,"abstract":"AbstractThe aim in this paper is to develop further and extend the application of the mathematical descriptions based on the previously developed local solute redistribution equation’ for the alloy-solidification process. To this end, a modified local solute redistribution equation for unidirectional solidification is presented and, using channel perturbation analysis based on this equation, a condition is developed for unstable flow and possible channel segregation which relates the interdendritic fluid velocity to the isotherm velocity. On assuming this condition to hold, a physical description related to the modified local solute redistribution equation is proposed, and a possible mechanism is presented for local remelting and the formation of channel segregation.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"37 1","pages":"81-84"},"PeriodicalIF":0.0,"publicationDate":"1983-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90051120","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-01-01DOI: 10.1179/030716983803291569
A. Afrouz, M. Collins, R. Pilkington
AbstractCreep tests have been performed on a commercial, 1Cr-0.5Mo low-alloy ferritic steel. Changes in carbide composition at 823 K have been measured as a function of exposure time using a scanning transmission electron microscope with an energy-dispersive X-ray analysis facility. The changes in the substitutional solute element concentrations in cementite are reported, and it is suggested that these changes could provide an aid to the estimation of effective exposure temperature for use in determining the remanent life of components made from this steel.
{"title":"Microstructural examination of 1Cr-O-5Mo steel during creep","authors":"A. Afrouz, M. Collins, R. Pilkington","doi":"10.1179/030716983803291569","DOIUrl":"https://doi.org/10.1179/030716983803291569","url":null,"abstract":"AbstractCreep tests have been performed on a commercial, 1Cr-0.5Mo low-alloy ferritic steel. Changes in carbide composition at 823 K have been measured as a function of exposure time using a scanning transmission electron microscope with an energy-dispersive X-ray analysis facility. The changes in the substitutional solute element concentrations in cementite are reported, and it is suggested that these changes could provide an aid to the estimation of effective exposure temperature for use in determining the remanent life of components made from this steel.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"6 1","pages":"461-463"},"PeriodicalIF":0.0,"publicationDate":"1983-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75347905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-01-01DOI: 10.1179/030716983803291253
Tongxi Yu, W. Johnson
AbstractCopper, brass, and mild steel strips were deformed under elastic-plastic bending in cylindrical dies by matched cylindrical punches, without the use of any lubrication, to study the history of the enforced deformation. Separation between the punch and the strip, the punch load-displacement relationship, and the elastic springback are described. The deformation model is found to be dominated by the parameter (Y/E) (l/h), where Y is the material yield stress, E its Young's modulus, h the strip thickness, and I the strip length. When the value of this parameter is small, the strip is described as ‘stiff‘, and when it is large, ‘slender‘. The complete deformation process may be divided into several stages, each associated with a number of loading points. The phenomena of multi-point loading and the effects of largest punch load have been successfully incorporated into an explanation of the non-uniformity in final curvature of the strip after springback.
{"title":"Cylindrical bending of metal strips","authors":"Tongxi Yu, W. Johnson","doi":"10.1179/030716983803291253","DOIUrl":"https://doi.org/10.1179/030716983803291253","url":null,"abstract":"AbstractCopper, brass, and mild steel strips were deformed under elastic-plastic bending in cylindrical dies by matched cylindrical punches, without the use of any lubrication, to study the history of the enforced deformation. Separation between the punch and the strip, the punch load-displacement relationship, and the elastic springback are described. The deformation model is found to be dominated by the parameter (Y/E) (l/h), where Y is the material yield stress, E its Young's modulus, h the strip thickness, and I the strip length. When the value of this parameter is small, the strip is described as ‘stiff‘, and when it is large, ‘slender‘. The complete deformation process may be divided into several stages, each associated with a number of loading points. The phenomena of multi-point loading and the effects of largest punch load have been successfully incorporated into an explanation of the non-uniformity in final curvature of the strip after springback.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"15 1","pages":"439-447"},"PeriodicalIF":0.0,"publicationDate":"1983-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79154468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-01-01DOI: 10.1179/030716983803291541
P. Fiorini, G. Giordano
AbstractThe effect on aging of adding 1% Zn and 0·31% Bi to an AI-6Mg alloy has been investigated by using resistivity and hardness measurements, tensile tests, and electron-microscope observation. Both after quenching, and after quenching and cold working, Zn addition distinctly increases the natural and artificial aging response of the alloy, modifing the GP zone formation process, the kinetics, and the microstructure of the Mg2Al3 phase precipitation. Evidence is also given of the combined effect of Zn and Bi addition in quenching experiments and of the presence of defects induced by cold working.
{"title":"Effect of Zn and Bi addition on precipitation process after quenching and cold vvorking Al-6Mg","authors":"P. Fiorini, G. Giordano","doi":"10.1179/030716983803291541","DOIUrl":"https://doi.org/10.1179/030716983803291541","url":null,"abstract":"AbstractThe effect on aging of adding 1% Zn and 0·31% Bi to an AI-6Mg alloy has been investigated by using resistivity and hardness measurements, tensile tests, and electron-microscope observation. Both after quenching, and after quenching and cold working, Zn addition distinctly increases the natural and artificial aging response of the alloy, modifing the GP zone formation process, the kinetics, and the microstructure of the Mg2Al3 phase precipitation. Evidence is also given of the combined effect of Zn and Bi addition in quenching experiments and of the presence of defects induced by cold working.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"20 1","pages":"52-56"},"PeriodicalIF":0.0,"publicationDate":"1983-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73379875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-01-01DOI: 10.1179/030716983803291325
G. Slattery
AbstractThe influence of base-alloy composition on the microstructure of aluminide coatings has been studied for a series of nickel-base alloys aluminized by the pack-cementation process. The microstructural features of the coatings formed on Nickel 200. Brightray Alloy C, Nimonic 80A, and Inconel 718 were evaluated by optical metallographic examination, together with microhardness surveys and scanning electron microscopy. The coating composition was determined from electron microprobe traverses of the coating layer and the aluminide phases were identified by X-ray diffraction examination of the bulk sample. The coatings were found to consist primarily of the nickel aluminide NiAI. although some Ni2Al3 was found to a lesser extent as a Widmanstatten structure in the coating on the Brightray alloy. A discontinuous, lamellar-type layer, enriched in chromium and other base-alloying elements with low solubility in the NiAI, was also observed at the coating/substrate interface. The coating could be precipitate...
{"title":"Microstructural aspects of aluminized coatings on nickel-base alloys","authors":"G. Slattery","doi":"10.1179/030716983803291325","DOIUrl":"https://doi.org/10.1179/030716983803291325","url":null,"abstract":"AbstractThe influence of base-alloy composition on the microstructure of aluminide coatings has been studied for a series of nickel-base alloys aluminized by the pack-cementation process. The microstructural features of the coatings formed on Nickel 200. Brightray Alloy C, Nimonic 80A, and Inconel 718 were evaluated by optical metallographic examination, together with microhardness surveys and scanning electron microscopy. The coating composition was determined from electron microprobe traverses of the coating layer and the aluminide phases were identified by X-ray diffraction examination of the bulk sample. The coatings were found to consist primarily of the nickel aluminide NiAI. although some Ni2Al3 was found to a lesser extent as a Widmanstatten structure in the coating on the Brightray alloy. A discontinuous, lamellar-type layer, enriched in chromium and other base-alloying elements with low solubility in the NiAI, was also observed at the coating/substrate interface. The coating could be precipitate...","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"15 1","pages":"41-51"},"PeriodicalIF":0.0,"publicationDate":"1983-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76080159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-01-01DOI: 10.1179/030716983803291947
W. Lee, B. Duggan
AbstractThe effect of different amounts of prior cold-rolling deformation on the anneal-hardening response of Cu-15Zn, Cu-30Zn, and supersaturated Cu-37Zn has been investigated. It is demonstrated that the hardness enhancement is highly dependent on the amount of deformation, the enhancement being very small below 40% and easily discernible at rolling strains above 5%. This change in hardness is associated with the formation of shear bands, a highly localized form of plastic deformation which is characteristic of cold-rolled low stacking fault energy materials. Cold rolling of the order of 5% performed after anneal hardening removes the strength increment and the material then behaves in a manner almost identical to samples not subjected to annealing.
{"title":"Anneal hardening in α-brass","authors":"W. Lee, B. Duggan","doi":"10.1179/030716983803291947","DOIUrl":"https://doi.org/10.1179/030716983803291947","url":null,"abstract":"AbstractThe effect of different amounts of prior cold-rolling deformation on the anneal-hardening response of Cu-15Zn, Cu-30Zn, and supersaturated Cu-37Zn has been investigated. It is demonstrated that the hardness enhancement is highly dependent on the amount of deformation, the enhancement being very small below 40% and easily discernible at rolling strains above 5%. This change in hardness is associated with the formation of shear bands, a highly localized form of plastic deformation which is characteristic of cold-rolled low stacking fault energy materials. Cold rolling of the order of 5% performed after anneal hardening removes the strength increment and the material then behaves in a manner almost identical to samples not subjected to annealing.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"53 83 1","pages":"85-88"},"PeriodicalIF":0.0,"publicationDate":"1983-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88831631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1983-01-01DOI: 10.1179/030716983803291433
E. Shelton, A. Rothwell, R. Coote
AbstractCanada has significant future natural gas reserve potential, particularly in the frontier areas of the Canadian Arctic. To utilize these energy resources, as well as those in Alaska, USA, will require major pipeline construction activity throughout the 1980s and 1990s. The first major natural gas pipeline, the Alaska Highway Gas Pipeline Project, is now under construction using high-strength (Grade 483), high-pressure line pipe. For future pipelines, the use of even higher strength line pipe materials (Grade 690) offers potential savings of the order of 25% in the cost of transporting gas. While materials at this strength level are currently feasible, further research is required to ensure their reliability in pipeline applications.
{"title":"Steel requirements for current and future Canadian gas pipeline systems","authors":"E. Shelton, A. Rothwell, R. Coote","doi":"10.1179/030716983803291433","DOIUrl":"https://doi.org/10.1179/030716983803291433","url":null,"abstract":"AbstractCanada has significant future natural gas reserve potential, particularly in the frontier areas of the Canadian Arctic. To utilize these energy resources, as well as those in Alaska, USA, will require major pipeline construction activity throughout the 1980s and 1990s. The first major natural gas pipeline, the Alaska Highway Gas Pipeline Project, is now under construction using high-strength (Grade 483), high-pressure line pipe. For future pipelines, the use of even higher strength line pipe materials (Grade 690) offers potential savings of the order of 25% in the cost of transporting gas. While materials at this strength level are currently feasible, further research is required to ensure their reliability in pipeline applications.","PeriodicalId":18409,"journal":{"name":"Metals technology","volume":"42 1","pages":"234-241"},"PeriodicalIF":0.0,"publicationDate":"1983-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88589608","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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